一个JAVA版的简单计算器

import java.awt.*; 
import javax.swing.*; 
import java.awt.event.*; 
class Counter extends WindowAdapter 
{ 
static JFrame f=new JFrame("计算器"); 
static JTextField text1=new JTextField("0."); 
static String source=""; 
static String cal=""; 
static String object=""; 
static boolean flag=false; 
static boolean flag1=true; 
static boolean flag2=false; 
public void init() 
{ 
try 
{ 
Container c=f.getContentPane(); 
JPanel pan1=new JPanel(); 
JButton b1=new JButton("1"); 
JButton b2=new JButton("2"); 
JButton b3=new JButton("3"); 
JButton b4=new JButton("4"); 
JButton b5=new JButton("5"); 
JButton b6=new JButton("6"); 
JButton b7=new JButton("7"); 
JButton b8=new JButton("8"); 
JButton b9=new JButton("9"); 
JButton b0=new JButton("0"); 
JButton b11=new JButton("+"); 

JButton b12=new JButton("-"); 
JButton b13=new JButton("*"); 
JButton b14=new JButton("/"); 
JButton b15=new JButton("."); 
JButton b16=new JButton("="); 
JButton bclar=new JButton("清零"); 
text1.setHorizontalAlignment(JTextField.RIGHT); 
c.add(text1,"North"); 
c.add(pan1); 
A aa=new A(); 
Result re=new Result(); 
Opertion op=new Opertion(); 
Clar cl=new Clar(); 
b1.addActionListener(aa); 
b2.addActionListener(aa); 
b3.addActionListener(aa); 
b4.addActionListener(aa); 
b5.addActionListener(aa); 
b6.addActionListener(aa); 
b7.addActionListener(aa); 
b8.addActionListener(aa); 
b9.addActionListener(aa); 
b0.addActionListener(aa); 
b11.addActionListener(op); 
b12.addActionListener(op); 
b13.addActionListener(op); 
b14.addActionListener(op); 
b16.addActionListener(re); 
b15.addActionListener(aa); 
bclar.addActionListener(cl);